Indicator for electric oscillations.



PATENTED NOV. 29, 1904.

A. SLABY. INDICATOR FOR ELECTRIC OSGILLATIONS.

' APPLICATION FILED JULY 26,1904.

N0 MODEL.

UNITED STATES Patented November 1&9, 1904.

PATENT OF ICE.

ADOLF SLAB nor GHABLOTTENBURG, GERMANY.

IINDIOATORFOR EL cTFuo osolLLATlons.

SPECIFIGATION f0rming part of Letters Patent Nd. .776;359, dated November 29, 1904.

' a Application filed July 26,1904. Serial 1%. 218,293; (No model.) 7 I To all whom it may concern.-

Be it known that LADOLE SLABY, professor, a Sub ect of theGerman Emperor, residing at Sophienstrasse 33, Charlottenburg, Germany,

have invented a certain new and useful Improvement in Indicators for Electric Oseilla c ear, and exact description, reference being had to the accompanying drawings, forming a part of this specification. y w

Among'the numerous instruments which are used for indicating electric oscillations one class may be distinguished by its great sensi tiveness. To this belongffor example, the

coherer, the microphone, in combination with a telephone, and the magnetic detector. The

same are suitedforthe reception of very weak electric indications','-and therefore are used at receivingstations for wireless telegraphy. Another'group, consisting of hot-wire ammeters, air-thermometers, sparking gaps, and the like, permits of aquantitative measurement of the potential and current strength, butsis far inferior to the first in sensibility and is therefore only used at transmitting-stations.

' The present invention relates to an indicator of electric oscillations of medium sensibility the employment of which is very convenient and the manufacture of, which by reason of its simplicity is remarkably cheap. The

phenomenon which led to the discovery of the same is as follows: When a strip of so-called gild paper was laid under the terminals of a resonator-coil, long lightning-like sparks of a greenish color were vproduced which were also visible in daylight. Asimple closed oscillating circuit served as wave-producer. The

effect due to the phenomenon was materially strengthened when small sheets covered with under the terminals of the resonator-coil, and

barium platino cyanid crystals were brought themaximum radiation resulted when gold-.

leaf was rubbed on the fluorescent sheet.

It has not hitherto beenpossible to explain or determine the phenomenon with any certainty from a physical standpoint. Probably the cathode-rays resulting from the discharges and possibly also the ultra-violet rays are the cause of the light phenomenon.

Figure 1 is a side elevation of my improved I employed.

indicator; Fig. 1 is alongitudinal section of the upper end thereof. Fig. 1 is a transverse section taken on the line 1 1 of Fig. 1. 2 .is a longitudinal section of an indicator, showing a modification.

In the accompanying drawings a formof construction of the inventionis-shown. An insulated copper wire of comparatively thin cross-section is wound in a close spiral on a glass tube a of about 0.7 5 inch diameter. The

Fig.

lower end .of the copper wire preferably is" conductively connected with a'metal handle I),

which handle is formed by a metal tube drawn over the glass tube. Theup'per-end of the copper wire is connected with a fluorescent sheet 0. The latter is sheet of paper which is coated on one side with barium platino cyanid crystals. Metal in a fine state of division is then applied to the rough crystal surface. This is preferably accomplished by rubbing gold-leaf on the crystalcoated surface. Instead of the barium platino cyanid any other fluorescent substance can be used. Also instead of gold other metals can be Preferably, however, precious metals which used for the purpose. The fluorescent sheet made in this way is preferably inserted in at the upper end of the glass tube, which is not wound with copper wire, and is by means of a preferably formed of a small are not subject to oxidation are p stopper d pressed, from inward against the glass wall.

Supposing the copper-wire coil is in resonance with aneighboring vibration system and oscillates in a wave of one-quarter the length of that of the primary system, whilethe end of the 'coil earthed by the hand of the person holding the rod forms the potential node, "the upper end connected with the fluorescent sheet forms the point of greatest variation of potential, the fluorescent body becomes powerfully illuminated and easily visible in full daylight.

In order to be able to use the indicator for determining the wave length or periods in an way and make the earthing of the coil independent of the body of the person holding the rod; atuning-rodf of metal is provided, which .95 oscillating system in a practical and .simpletoo preferably of lead, serving for earthing the rod. .'In using the apparatus the plate is laid on the ground, this fully sufiicing forlthe establishment of a good earth connection of the rod f, and then the metal rod f is moved along the coil until the fluorescent body is brightly illuminated. A scale arranged on the coil allowsthe Wave length or period at which resonance commences to be seen. It is under- 1o stood therefrom that the adjoining oscillating system from which the excitation proceeds oscillates in correspondence or with equal wave length. The scale can be united in various ways with the rod. It is preferable to indicate I 5 it with suitable colors on the wire winding itself. The excitation of the coil by the system to be tested can take place in various ways. If the coil is brought very near to the vibration system, especially to the coils thereof, the excitation of the indicator-coil would take place by means of electromagnetic radiation, while in cases where the indicator-coil is held further removed from theoscillating system an electrostatic transfer would take place principally through the earth.

( In general in all transfers inductive coupling between the secondary coil and the sys tem to be tested is shown to be essential, while direct coupling, for example; by the. conduct- 3o ive junction of the secondary coil and the system is not advisable, and considerable errors of ten to twenty per cent. result therefrom.

In order to increase the sensibility of the indicator or the light action of the light-sheet,

3 5 it is preferable to bring the lower end of the coil connected with the handle into connection with the fluorescent sheet, which can easily be done, asshown in Fig. 2, by carrying the end of the coil from below upward through 40 the glass tube a. The maximum light action in this case coincides with the greatest difference of potential existing between the two ends of the coil. In order to be able also to measure with the indicator comparatively long waves without exceeding reasonable limits in the length-of the rod, it is preferable to use a ..wire for making the coil which is wound spirally round an insulating-corefor example, round silk thread.

5 Having explained my invention, what I claim, and, desire'to secure by Letters Patent, I

1. A wave-indicator consistingof aresonator in combination with fluorescent substances in such a way that these bodies are illuminatedwhen electric oscillations arise in 'the resonator.

' 2. Wave-indicator consisting of a resonator in combination with fluorescent substances ar- 50 ranged at places of maximum potential of the resonator and in such a way that the ubstances are illuminated when electric osc1lla tions arise in the resonator.

3. Nave-indicator consisting of a resonator in the form ofa wire coil in oombination with fluorescent substances at places of maximum potential of the coil.v

4:. Wave-indicator consisting of a wire coil which can be earthed at one point and whose other free end is connected with fluorescent substances.

5. Wave-indicator consistingof a resonator in combination with fluorescent substances at points of maximum potential of the resonator in which metal in finely-divided form is applied to the fluorescent substance.

6. Wave-indicator consisting of a resonator in the form of a wire coil one end of which is connected with a metal handle, in combination" with fluorescent substances to which metal in finely-divided form is applied at places of maximum potential.

7. Wave-indicator consisting of a wire coil one end of which is earthed and 'whose other free end stands in connection with fluorescent substances to which metal in finely-divided form is applied.

8. Wave-indicator consisting of a wire coil one end of which stands in connection with fluorescent substances to which metal in finelydivided form isapplied and an arrangement for tuning the coil to a neighboring oscillating system. c

9. Wave-indicator consisting of a wire coil one end of which is connected with a fluorescent substance to which metal in finely-divided form is applied in combination with an earthed arrangement for tuning the coil to a neigbor-' ing oscillating system and a scale divided into wave lengths or oscillation periods.

10. Wave-indicator consistingof a wire coil whose upper end is connected with barium platino cyanid crystals to which precious metal in finely-divided form is applied in combination with an earthe'd tuning arrangement for earthing'a suitable point of the coil, and

with a scale divided into Wave lengths or oscillation periods.

l1. Wave-indicator consisting of a wire coil both ends of which are connected. with a fluorescent substance, and an arrangement for earthing a suitable point of the coil for the purpose of tuning the same to aneighbor-ing oscillating system.

In witness whereof I hereunto subscribe my name this 9th day of July, A. D. 1904:.

' ADOLF SLABY. Witnesses: 1 r

' HENRY HAsPnR,

WOLDEMAR HAUPT. 

